Carburetor



R. SQ CNNINGHAM March 8 1927.

GARBURETO'R Filed March 10, 1925 3 Shets-Sheet 1 n 2 e o/ m y Q 3 2 n Il r .Illl 01|@ Ol! M March 8 192,7.

R. s. CUNNINGHAM GARBURETOR Filed March 10, 1925 3 Sheets-Sheet 2 March 8 1927.

Filed March l0, 1925 O OOOOOOOOOOO 3 Sheets-Sheet 5 Patented Mar. 8, 1927.

UNITED STATES;

IrrvrrzNT OFFICE.

ROY S. CUNNINGHAM, 0F LOS ANGELES, CALIFORNIA, ASSIGNOR 0F ONE-THIRD T0 FRANK J. HASSELL` AND ONE-THIRD T0 JAMES R. KELL, BOTE OF LOS ANGELES,

CALIFORNIA.

CARBURETOR.

This invention relates to carburetors.

An .object is to provide a carburetor having valve means for automatically controlling the richness of a fuel mixture to a combustion engine while running at idling speed.

An object is to provide a carburetor which is wholly free of spring means, and which is provided with a. valve system in .which the valves are balanced against lateral pressure and are provided with a dash-pot device to prevent liuttering action.

An object is to provide stove, burning gasoline, means for instantly heating yair prior to its passage into-the main jet mixing chamber when starting a cold motor; to provide for automatic cut down of flow .of the air from the stove as the exhaust side "of the engine warms up; and to provide for flow fromthe stove to the mixingg chamber when the motor turns at more than an ordinary running speed so as to obtain better carburetion at the higher speeds with a saving of fuel.

A further object is to provide for the full cut-off of flow from the carburetor when the motor is to be used as a brake for a vehicle.

i A general Objectis to provide a carburetor functioning economically in consumption of gasoline.

Other objects and advantages will be made manifest in the following specification of apparatus of one embodiment of the invention; it being understood that modifications, variations and adaptations may be resorted to within the 'spirit and scope of the invention as is here claimed.

Figure 1 Iis a plan of the carburetor.

Figure 2 is an elevation and partial section.

Figure 3 is a section on line 3 3 of Fig. 1.

The carburetor has a shell, unitary or sectional as may be expedient, including a bowl 2 forming a chamber for a oat 3, covered by a top plate 4, secured as by screws 5. The float has a lateral lever arm 6 pivotally supported on a ball-headed post 7 adj ustably extending through the bottom of the bowl.

The lever arm 6 carries a needle valve 8 movable toward and from a seat 9 to control inflow of fuel from a supply means 10.

rlhe float 3 is perforated to clear a xeol tubular trunk 11, screened at its inlet 12, extending above the float and across to the side wall of the bowl. 'llhis has diagonal ducts 13 and 1e, Fig. 2, from the trunk.

The port 13 leads to a well 15 having an adjustable screw 16 pointed at its upper end to regulate the streams of liquid fuel drawn from the nozzle head 17 of the well, which latter is disposed in a main jet, mixing chamber 18 here of cylindrical form and having a lateral air port 19 opening into an intermediate air chamber 20 having a mouth 21 ina vertical wall 22 at one side of the top of the bowl. l

The upper portion of the mixing chamber 18 flares outwardly and thence extends upwardly as a fuel column 23 adapted for attachment to the intakemanifold of a motor.

In the column is the usual main throttle valve 25, which when closed allows for passage of a-fuel stream to enable idlingvof the motor. 4

A feature of the invention is a lbrake throttle 26 disposed in the column 23 above the main throttle and by which fuel iiow can be practically entirely cut off and so prevent fuel consumption as when a vehicle (carrying the motor) maybe running down hill in gear; especially in low gear. If the spark of the motor is shut off while running down hill the 'unburnt gas will leak to and dilute the motor oil. With my present brake throttle the spark can be left onwithout giv- 1ng power to the motor since the brake throttle practically elimina-tes suction of any fuel to the motor.

Around the main nozzle 17 is arranged a contracted choke valve 27 having a cylindrical lower part 28 working not tightly, in a dash pot 29 having vent ports 30- in its bottom. The `pot comprises an annulus spaced around the well 15 and allowing for upflow 0f agirgffrom a hot air pipe 32. The top lip 27a. 'f the valve 27 registers with the near portion of theI flare when the valve is at rest on the bottom of the dash pot. l

The air port 19 is opposite the contracted valve part 27 Aand is below its lip 27 .4

Means arefprovided for supplying heated air tothe main valve 27 when starting a cold motorfand such means includes a stove cl'nmy 4ber 34 having a top connection- 33 from which the bot air pipe 32 leads down to the bottom of the chamber 18. The stove has a convergent lower portion 35 and a valvel chamberBG in which works a balanced spoolvalve 37 fitting in a dash-ring 38 in champ ber 20. j

'lfhespoolvalve has a ange 37 tting the.

lll@

lower portion of the flare 35 and allowing increase of stream flow when moving upwardly therein. A lateral port 36a leads from chamber 20 into chamber 36 to provide air to the stove.

Projecting up into and clear of the dashring (or dash-pot) 38 and into the spool valve `37 is a fuel nozzle 39 past which air from chamber 20 may flow through, the valve 37 and thence into the lower end of a perforated burner tube 4() spa-ced from and surrounded by the stove chamber 34.

Extending into the burner tube is an ignition device, such asia constantly hot coil or a sparking plug 41. Cold air entering port 36a lifts and passes the stoveA valve 37 and rises around the tube 41, which is heated by burning fuel, and thence passes to connection 33 and down pipe 32 to the main jet valve 27, to which fuel 'is led by duct 14.

, Another feature of the invention includes means for automatically varying the fuelf quality passing beyond the main throttle 25. This means involves an auxiliary, balanced valve 44 having a contracted waist and cylindrical lower end to fit and play in a dash-pot ring 45 opening into an air pocket 46 having an upwardly inclined duct 47 leading into the stove chamber`34. The auxiliary valve 44 has a cross wall 44a closing 1t so that suction in the pocket 46 tends to pull the valve down so that'its top 11p 44b lies below an annular series of air holes 48 leading into an annular conduit 49 in a cylindrical wall 50 fitting the valve lip. 44". The conduit 49 has a passage-way terminatin in an aperture 51 opening into the main co umn 23 just above the main throttle 25. When this is closed for idling the motor suction effect in conduit 49 tends to lift the balanced valve 44 and this allows cold air to How from chamber 20 into a by-pass 52 leading into the auxiliary valve cylinder 50. As the valve lip 44b passes across the holes 48 fresh air flows to the fuel column 23 and thus fuel is leaned. As the motor slows the valve 44 retracts and reduces air flow to conduit 49.

This auxiliary valve 44 also comes into action when the motor is running fast enough, on open throttle, to produce such low press ure in the cylinde1\50 that the valve will move up to supply more air.

Itwill be seen thatI the several lipped valves 27, 37 and 44 are each of lateral pressure balance type, and that each has a skirt portion to act with a cushioning elfect in their annular hollow dashJpot supports, therefore eliminating uttering effect while in action.

The operation of the cavbureter is as follows:

Starting a cold matar the main throttle 25 may' be `opened allie (brake throttle" 26 being full open) aid as the mQtOr is turnedl over (by crank or starter) suction pulls fuel from the main jet 17.' Starting suction is insuiicient to open valve 27 and its effect extends back through pipe 32, to the stove valve 37, and also to a. hot air line 55 having a valve 56 opened and closedby a thermostatic device 57 disposed in a jacket 58 encompassing a part of the motor exhaust flue E, Fig. 2.

The motor being cold, valve 56 is closed and all suction effort is exerted on the stove valve 37. rlhe result is that air is drawn from chamber 20 through the valve 37 and fuelis drawn -from nozzle 39 up into the burner tube where it is lighted by the energized device 41. Air also flows into port 36a and past the raised choke lip 37 and thence along the outside of the hot tube 41, becoming thereby heated and passing on to the pipe 32 and up through the choke valve 27. The hot air from the stove quickly absorbs the fuel spray from the nozzle andbecomes highly, quickly effective in driving the motor on fuel. As the motor heats and picks un speed the hot exhaust opens the thermostatic valve 56 and hot air then flows to the pipe 32 thus lowering tension in the stove 34 so that valve 37 recedes and reduces stove fuel supply. 1

When the motor vspeed accelerates from starting speed and opening of the throttle 25, valve 27 comes into action and automatically regulates air inlet past the choke flare 22 into the column 23. Y

At very high speed, and open throttle, the

auxiliary valve 44 admits additional air, and A also when the throttle is closed.

At high speed some air will-be drawn through the stove and to the pipe 32 and this will be effective in warming up the fuel in the intake. 4

It will be seen that the stove comes into veffect immediately on startinga cold motor because the hot air pipe 32 yis otherwise closed at the thermostatic valve 56. When the exhaust Hue E warms up the valve 56 opens and hot air is drawn to the choke valve 27, and thus effective, quick spray absorption is accomplished independently of the stove 34 which passes out of action as the exhaust heats up,vbut will again serve if suction (from high speed-)-`a1ects the valve.

The bowl 2 may be'ivented to the intake column 22 by a vent tube 58. y

Since the air valve 56 is closed when starting acold motor, it will be seen that'the stove valve 37 serves as an automatic choke causing a strong pull on fuel in the main jet 17 as the motor is given its initial turns.

To control the freedom of action of the several valves 27, 37 and 44 vin their vdashcups, these may be provided with regulating means, as. valve screws 60 (only one'being shown). By this means speed of rise and fall of the valves may be very closely regulated by controllin inlet and escape of air independently of t e ports in the c-ups for the valves.

Limit of upward movements of the valves 27 and'37 may be determined by any suitable contiguous parts of the carburetor, as pins, and valve 44 is stopped by cap 50a.

What is claimed is: 0

l. Carbureting apparatus including, 1n combination with a motor, a main jet'and mixing means, and a fuel burning stove having an air passageway leading to the jet and mixing means, .and exhaustheated air supply means for cutting out the st ove after the associated motor is heated'.`

2. Carbureting apparatus including a mixing chamber and a main jet therefor, a stove chamber communicating with the main jet air passageway, and air actuated valve means for controlling airand fuel flow to the stove; 'said valve being of hollow balance type, and a fuel nozzle in the valve. y

3. Carbureting apparatus including a mixing chamber and a main jet therein, an upright stove chamber having at its top an outlet communicating with the jet cham ber, a perforated burner tube disposed upright in the stove chamber leaving an unobstructed flow passage to the out-let, and fuel supply means feeding fuel to the ,tube to heat it and air flowing past the tube to the chamber outlet and an automatically retracted, air balanced and actuated fuel control valve surrounding the fuel feed means.

4. Garbureting apparatus including a Y mixing chamber and a main jet and a hollow valve therein, a stove chamber .contiguous to and communicating with the bottom of the jet chamber through the valve, a perforated burner tube disposed in the stove chamber, and fuel supply means feeding fuel to the tube to heat it and air flowing past the tube, and an automatic valve for controlling fuel and air to the stove.

5. Carbureting apparatus including a main jet Iand a mixing chamber receiving spray therefrom, an air supply means having an intake adljacent to an exhaust flue,

a thermostatic va ve to close the said intake when flue is cold, and fuel burning stove means communicating with the air supply means to supply hot air before the exhaust flue is heated, and a stove valve controlled by operation of the thermostatic valve.

6. Carbureting apparatus including a man jet and a mixing chamber receiving spray therefrom, an air supply means havmg an intake adjacent to an exhaustplue,

'fuel from the jet, and secondary means for supplying air in balanced effect around t-he A valve; said. valve operative to ladmit air from the secondary means to the mixing chamber, band...,av'alve controlled fuel burning chamber for supplying hot air to the mixing chamber'and past the jet, before an associated motor may heat up.

8. Carbureting apparatus including a mixing chamber having a throttle valve, a choke valve and a jet therein for supplying fuel spray tothe chamber, a hot tube chamber for supplying hot air, when starting, to the choke lvalve passage, and an auxiliary valve in a chamber communicating with the ltube chamber for supplying air to the mixing chamber at a point beyond the throttle.

9. Carbureting .apparatus including a mixing" chamber having a throttle valve, a hollow choke valve and a jet therein for supplying fuel spray through the valve to lthe mixing chamber, a stove chamber for supply-ing hot air through the choke valve for startin an auxiliary air chamber having Va suctionpocket leading only to Vthe stove"chamber,` and an auxiliary air valve therein between the stove chamber and chamber above the throttle.

10. Carbureting apparatus including a main jet and mixing means, a valve, fuel burning stove serving hot air to the mixing means, and a thermosensitive, exhaust heated air supply means communicating with the stove outlet tofbreak How therefrom when the exhaust becomes heated.

11. Carbureting apparatus including a shell having a stove chamber and a mixing chamber, a hollow Vmain valve in the mixing chamber, a flue from lthe top of the lll) stove chamber to'the bottomof the valve and mixing chamber, a fuel valve for the stove, and exhaust heated air supply means for by-passmg au' around the stove valve.

ROY S. CUNNINGHAM. 

